The competition, set for Aug. 23, 2014, is a unique adventure race – the only 100-mile mountain bike race in Latin America, and the only race in the world to circumnavigate an active volcano, according to press information.

Mountain bikers from all over will test their stamina and skill riding 100 miles (160 km) clockwise around the volcano through five microclimates – from the Northern Pacific dry plains of Guanacaste up over Costa Rica’s Continental Divide to lush cloud forests, across rivers, around the smoldering Rincón de la Vieja Volcano to where it meets the Miravalles Volcano, and back to the finish line.

Starting at 5:30 a.m. from the Las Pailas entrance to the Rincon de la Vieja Volcano National Park, competitors have 12 hours to ride gravel roads, red clay tracks, river and volcanic rock trails, smooth white ash roads and “dog’s teeth” calcite rock trails – with close to 11,000 feet of elevation gain – to reach the finish.